JPH07150395A - Divided electrode plating device and method for determining current value - Google Patents

Abstract

PURPOSE:To determine a current value to uniformize a plating film thickness with a plating device using divided anodes by expressing relations of a current, area, film thickness, etc., by an equation using a matrix. CONSTITUTION:An area dividing procedure 101 determines the areas to be plated of the respective regions where the range to be plated of a plating object is divided to the number of electrodes in correspondence to the number of electrodes. A matrix expressing means 102 expresses the relations between the areas to be plated of the respeictive range determined by this area dividing procedure 101, the target plating film thickness and the plating current value. A matrix analyzing procedure 103 determines the respective elements of the matrix by using the past plating execution data by using the matrix expression determined by this matrix expressing procedure 102. A current value calculating means 104 calculates the plating current value in accordance with the respective elements of the matrix determined by this matrix analyzing procedure 103.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus, and more particularly to a split electrode plating apparatus in which an anode is divided and a current value can be set individually for each anode, and a current of each anode of the plating apparatus. Regarding value determination method.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to the drawings. FIG. 4 is a diagram showing an example of a conventional technique disclosed in Japanese Patent Laid-Open No. 61-281896.

The plating apparatus shown in FIG. 4 has a power source 41 for generating a current for plating an object to be plated, a plurality of divided anodes 47 separated by partition walls 48, and a current for flowing the divided anodes. A changeover switch 43 that can be selected by the connected power supply circuit 45 or a resistance circuit 44 that makes it difficult for the current to flow, and when the current flowing through the power supply circuit 45 exceeds a specified value, it is detected and the changeover switch is set to the resistance switch A current detector 43 that switches to the 44 side,
A timer 46 is included which, when the changeover switch 43 is connected to the resistance circuit 44 side, returns to the original power supply circuit 45 side after a set time has elapsed.

In this plating apparatus, a divided anode 47 is provided corresponding to a printed circuit board terminal which is an object to be plated, a current detector 42 and a changeover switch 43 are provided in series, and a feeding circuit 44 and a resistance circuit 45 are switched. Therefore, in the case of plating with one anode, it is possible to control the unevenness of the plating thickness due to the location of the terminal, which is unavoidable, so that it can be controlled for each individual terminal (for each pin). The maximum current density can be made higher, and accordingly, the plating processing time can be shortened.

[0005]

Although the conventional plating apparatus described above can control the current value for each divided anode, the adjustment of the current value in this case is only for the plating object having the same shape. For the purpose of controlling the variation in the plating thickness with respect to the anode, when the shape of the plating target corresponding to the split anode and the area to be plated are different, repeat the experiment (trial and error) and gradually approach the target. There is no other way around, and there is the problem that it cannot be handled easily.

An object of the present invention is to determine a plating apparatus and a current value which can control and make uniform the thickness variation of the plating even when the shape and area of the plating object corresponding to the divided anodes are different. To provide a method.

[0007]

A split electrode plating apparatus according to the first aspect of the present invention includes a power source unit for supplying a plating current required for plating an object to be plated by a plurality of power sources, and a plurality of power sources in a plating tank. An electrode part for partitioning an object to be plated with a current supplied from the power supply part to the same number of divided anodes as the number of the power supplies separated by partition walls, and a current for determining a current value set in the power supply of the power supply part And a control unit for issuing a value command.

The plating current determining method of the second invention is such that the range to be plated on the object to be plated is made the same as the number of electrodes corresponding to the number of divisions of the divided anodes of the electrode section of the divided electrode plating apparatus of the first invention. An area division procedure for obtaining the area to be plated in each divided range, and a matrix expression procedure for expressing the relationship between the area to be plated in each range obtained in the area division procedure, the target plating film thickness, and the plating current value in a matrix. , A plating current value based on each matrix element obtained by the matrix analysis procedure and each matrix element obtained by the matrix analysis procedure by using the past matrix implementation data obtained by the matrix expression procedure to obtain each element of the matrix Is included in the current value calculation procedure.

[0009]

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. The split electrode plating apparatus shown in FIG. 1 includes a power supply unit 1 for supplying a plating current necessary for plating an object 3 to be plated by a power supply 11 having the number of split anodes 21 in an electrode unit 2, and a plating tank 4. An electrode part 2 for plating the object 3 to be plated by the current supplied from the power supply part 1 by the divided anodes 21 separated by the partition wall 22 and a current value set in the power supply 11 of the power supply part 1 are determined. It is configured to include a control unit 5 that issues a current value command 51 for performing.

FIG. 2 is a flow chart showing a procedure for determining a current value command 51 to be set in each power supply 11 of the split electrode plating apparatus shown in FIG. The plating current value determining procedure shown in FIG. 2 is an area dividing procedure 101 for dividing the range to be plated of the object to be plated into the same number of ranges as the number of electrodes and obtaining the area to be plated in each range. The matrix expression procedure 102 for expressing the relationship between the area to be plated, the target plating film thickness, and the plating current value in each range obtained in the area division procedure 101 by a matrix, and the matrix expression obtained in the matrix expression procedure 102 It includes a matrix analysis procedure 103 for obtaining each element of the matrix using the plating execution data, and a current value calculation procedure 104 for calculating a plating current value based on each element of the matrix obtained in the matrix analysis procedure 103. It

When the object 3 to be plated is plated in the plating apparatus shown in FIG.
The value of the current flowing through the power source 11 of the power source unit 1 is determined by the above. However, by setting each of the power sources 11 as a current source, a constant current value can be set.

The procedure for obtaining the current value command 51 will be described below. Consider a case where the anode is divided into three areas in each of the vertical and horizontal directions as shown in FIG.

In the area division procedure 101, the plating target 3
Also, consider a case where the split anode 21 is divided into nine parts according to A1 to A9, and each range is adjusted to the split anode 21 and set to P.
1 to P9. Determine the area to be plated within each range. Since the area to be plated is the area of the wiring pattern in the case of the multilayer ceramic substrate, it is obtained using CAD data when designing the multilayer ceramic substrate. The CAD data is input with information about the coordinates of the start and end points of the wiring pattern and the width of the wiring pattern, and using this information, P1
The area to be plated within each range of to P9 is obtained. The total area to be plated may be the sum of the areas P1 to P9.

Hereinafter, as shown in FIG. 3A, the current values flowing through the divided anodes A1 to A9 of the electrode portion 2 are i1 to i1.
i9 and P1 to P9 are the ranges of the plating object 3 corresponding to the respective anodes A1 to A9, and the range P1
Areas to be plated in each range from to P9 are s1 to s9. The target plating film thickness in the range P1 to P9 of the object 3 to be plated is set to d1 to d9. The relationship between the area to be plated, the target plating film thickness, and the plating current value in the matrix expression procedure 102 is derived from the following relationship.

The relationship between the current value and the film thickness is expressed by the following equation. i = ρds / (kt) (A) However, d: average film thickness k: electrochemical equivalent i: current t: plating time s: plating area ρ: metal density At this time, the range P1 of the plating object 3 is filmed. The current value required for plating to the thickness d1 is as follows when the plating time t is constant. ρd1s1 / (kt) (A) When the plating target 3 is plated in the plating tank 4, as shown in FIG.
As shown in (b), the range P of the current i1 flowing through the electrode A1
It is assumed that the current flowing into 1 is a current value corresponding to c1,1 times the current value (A), and the current flowing into the range P2 is c1,2 times the current i1. Similarly, the current flowing from the electrode An to the range Pm is cn, m times the current ρdmsm / (kt) required for the range Pm.

From these relationships, the following equation is derived. I = ρ / (kt) · CSD (B)

[0018]

In the current value calculation procedure 104, each element of the matrix C, ci, j, is obtained using the matrix expression equation (B) obtained in the matrix expression procedure 103. The matrix C can be estimated by the least square method or the like by using the data of the past plating current value, the area to be plated, and the measured film thickness after plating. Matrix C
The current value command 51 set by the control unit 5 can be calculated by using the matrix expression (B).

In this way, by calculating the value of the current flowing through each of the divided anodes based on the past data, it is possible to perform plating that reflects the past data, so that the plating film thickness is uniform. By using more data that can be obtained, it is possible to obtain a current value with which the plating film thickness can be made uniform even for a multilayer ceramic substrate having a new wiring pattern, by greatly reducing the number of trials and errors.

Further, by using this split plating apparatus, not only the multi-layer ceramic substrate but also a plating object which generally uses a plating apparatus of a type which performs plating for a fixed time with a preset current value is used. If so, it is possible to adjust the plating film thickness by using the split plating apparatus and the current value determining method of the present invention.
For example, in FIG. 3A, the ranges P1 to P3 are changed to the range P4.
It can also be applied to the case of making the thickness about 1 μm thicker than P9.

[0022]

[Effects of the Invention] By expressing the relationship of current, area, film thickness, etc. for a split electrode plating apparatus using a matrix, the area to be plated on the object to be plated and the split anode can be defined using the past example. It is possible to determine the current value that makes the plating film thickness uniform by determining the divided area according to the divided area, and it is possible to reduce the cost by reducing the number of trials for plating the object to be plated until the current value set for the divided anode is determined. Leads to.

Further, by using this split plating apparatus, not only a multi-layer ceramic substrate but also a plating object which generally uses a plating apparatus of a type for performing plating for a fixed time with a set current value. For example, it is possible to adjust the plating film thickness by using the split plating apparatus and the current value determining method of the present invention.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure for determining a plating current of the plating apparatus shown in FIG.

3A and 3B are diagrams showing a relationship between an electrode portion and an object to be plated in the embodiment of FIG.

FIG. 4 is a configuration diagram showing an example of a conventional plating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 power supply section 2 electrode section 3 plating object 4 plating tank 5 control section 11 power supply 12 variable resistance 21 split anode 22 partition wall 51 current value command 41 power supply 42 current detector 43 changeover switch 44 resistance circuit 45 power supply circuit 46 timer 47 split anode 48 partition wall 51 current value command 101 area division procedure 102 matrix expression procedure 103 matrix analysis procedure 104 current value calculation procedure

Claims (2)

[Claims] 1. A power supply unit for supplying a plating current required for plating an object to be plated by a plurality of power supplies,
An electrode section for plating an object to be plated with a current supplied from the power source section to the same number of divided anodes as the number of power sources divided by a plurality of partition walls in the plating tank, and a current value set for the power source of the power source section. And a controller for issuing a current value command for determining the split electrode plating apparatus. 2. The area to be plated in each range obtained by dividing the range to be plated of the object to be plated by the same number as the number of electrodes corresponding to the number of divisions of the divided anode of the electrode section of the divided electrode plating apparatus according to claim 1. The area division procedure for obtaining, the matrix expression procedure for expressing the relationship between the area to be plated, the target plating film thickness and the plating current value in each range obtained in the area division procedure in a matrix, and the matrix obtained in the matrix expression procedure It includes a matrix analysis procedure for obtaining each element of the matrix using the past plating execution data using the expression, and a current value calculation procedure for calculating the plating current value based on each element of the matrix obtained by the matrix analysis procedure. A method for determining a plating current, which is characterized in that